Is Sitting the New Smoking - What Do We Know

Recent studies have linked prolonged sitting with similar health risks as obesity and smoking. In fact the analysis of 13 different studies found that 8 hours a day of sitting with no physical activity raised the risks of developing breast cancer, colon cancer, lung cancer, type 2 diabetes, heart disease, obesity and depression. Other adjunct conditions are high blood pressure, high blood sugar, excess abdominal fat, and abnormal cholesterol levels. In short sitting too often or too long significantly increases your chance of dying from cardiovascular disease or cancer.

Consider that according to the CDC the average American spends over 8 hours a day sitting. For many office workers that number can climb to 15 hours or more especially when you add in commuting. Let’s not forget to add in an average of three hours of entertainment screen time per day as well. John Hopkins states that physically active jobs now make up less than 20% of all jobs in America. It’s not hard to see that all this lack of physical activity can lead to bad things. The pandemic has likely only added to the problem as more people work from home usually while seated in front of their computers, tablets or smart phones.

So how can prolonged sitting do this? Well, for one, when you are sitting you use less energy; as in calories. Your body’s ability to process fats decreases as lipoprotein lipase (an essential enzyme for breaking down fats) deceases by as much as 90 percent. When your body can’t utilize fats where does it go? It gets stored of course. Blood flow also slows allowing fatty acids to build up in blood vessels leading to cardiovascular disease. Insulin resistance can also set in which is a cause of type 2 diabetes and obesity; both leading causes of heart disease.  That brings us back to blood flow, remember the heart pushes blood out through the arteries, but venous return (blood returning to the heart) occurs from muscular contraction forcing blood back up through the veins. Sitting restricts muscular contraction particularly in the lower extremities that leads us to increased risks of blood clots which among other things can cause stroke.    

Prolonged sitting is not the new smoking and here is why

Prolonged sitting can increase the risk of premature death and chronic disease by about 10-20%. Smoking on the other hand increases this risk by 180% and the risk of lung cancer by 1000%. Sitting is also not a danger to those around us. More over Meta studies have shown the risk is mainly in those who are physically less active. Sitting posed little increased risk association for those who are otherwise most active. New studies try to quantify the number of hours at 10 hours or more of sitting as the risk threshold for even active people.

Countering the Effects of Prolonged Sitting

The World Health Organization recently came out with guidelines on physical activity and sedentary behavior. Their advice is 30-40 minutes of moderate to vigorous activity can reduce the risks. There is still not enough evidence to suggest the maximum thresholds of activity and sedentary behavior just yet. Another meta-data study of a million people found that 60-75 minutes of moderate activity were required to counter the effect.  This does not mean you have to go to the gym to achieve these numbers activity can come from many sources. In fact breaking it up into smaller bits and pieces might even be better. Things like getting up from your desk and walking around for several minutes, standing while talking on the phone, taking the stairs, walking over to deliver a message down the hall rather than through email.  How about parking a little farther away or walking to a nearby errand, skip the escalator or elevator for 2-3 floors, even fidgeting while sitting down or doing some leg and glute clenching at your desk adds up, and of course doing an actually workout probably wouldn’t hurt either. Not enough space here to talk about all those additional benefits from doing that.

The takeaway here is the more you move the healthier you’ll be and that movement comes in many forms. Think gardening or washing your car that counts too. You have endless possibilities here all you have to do is try. You can do this even if it’s just a few minutes at a time. 

References:

Science Daily – Aim to increase weekly recommended physical activity levels to offset health harms of prolonged sitting

Mayo Clinic – Sitting Risks: How harmful is too much sitting?

Heart Foundation.org – Is sitting the new smoking?

Hopkinsmedicine.org – Sitting Disease: How a Sedentary Lifestyle Affects Heart Health

Cuu.com – Americans Sit Too Much, CDC Says

The Conversation.com – Why Siting Is Not the New Smoking